NAME

var.ops - Variable Ops

DESCRIPTION

These operations deal with both lexical and global variables, as well as the symbol tables that contain them.

Lexical variable ops

Operations to create, modify and delete lexical variables.

new_pad(in INT): Create a new lexical scope pad with static nesting depth $1 and push it onto the lexical scope stack. Static depths 0 through $1 - 1, inclusive, are copied from the current static nesting.
new_pad(out PMC, in INT): Create a new lexical scope pad with static nesting depth $2 and store it in $1 (do NOT push on the stack). Static depths 0 through $2 - 1, inclusive, are copied from the current static nesting.
push_pad(in PMC): Push the scratchpad in $1 onto the lexical scope stack.
pop_pad(): Pop the current lexical scope pad off the stack
pop_pad(out PMC): Pop the current lexical scope pad off the stack and store it in $1 (XXX JPS: not implemented yet).
peek_pad(out PMC): Store the current lexical scope pad (i.e. the one at the top of the lexical pad stack) in $1.
store_lex(in STR, in PMC): Store object $2 as lexical symbol $1. $1 must have already been created at some static depth.
store_lex(in INT, in STR, in PMC): Store object $3 as lexical $2 at depth $1. If [$1, $2] does not exist, it will be created. If $1 is negative, count out from the current lexical scope; otherwise, count in from the outermost scope. So store_lex -1, .... will operate on the current pad. Lexicals can be restrieved by index too: the index is generated in storage order.
store_lex(in INT, in INT, in PMC): Store object $3 at lexical position $2 at depth $1. If [$1, $2] does not exist, it will be created. If $1 is negative, count out from the current lexical scope; otherwise, count in from the outermost scope. So store_lex -1, .... will operate on the current pad. Lexicals stored by index can only be retrieved by this index.
find_lex(out PMC, in STR): Find the lexical variable named $2 (at any depth) and store it in $1.
find_lex(out PMC, in INT, in STR): Find the lexical variable named $3 at depth $2 and store it in $1. If $2 is negative the, count out from the current lexical scope; otherwise, count up from the outermost scope.
find_lex(out PMC, in INT): Find the lexical number $2 at the topmost pad.
find_lex(out PMC, in INT, in INT): Find the lexical variable at position $3 at depth $2 and store it in $1. If $2 is negative the, count out from the current lexical scope; otherwise, count up from the outermost scope.

Global variable ops

Operations to modify global variables

store_global(in STR, in PMC): Store global $2 as global symbol $1
store_global(in STR, in STR, in PMC): Store global $3 as global symbol $2 in namespace $1
store_global(in PMC, in STR, in PMC): Store global $3 as global symbol $2 in namespace $1
find_global(out PMC, in STR): Find the global named $2 and store it in $1. If the global doesn't exist either throws an exception or sets $1 to undef, depending on current errors settings, s. errorson.
find_global(out PMC, in STR, in STR): Find the global named $3 in namespace $2 and store it in $1. If the global doesn't exist either throws an exception or sets $1 to undef, depending on current errors settings, s. errorson.
find_global(out PMC, in PMC, in STR): Find the global named $3 in the namespace specified by the key in $2 and store it in $1. If the global doesn't exist either throws an exception or sets $1 to undef, depending on current errors settings, s. errorson.

COPYRIGHT

LICENSE

This program is free software. It is subject to the same license as the Parrot interpreter itself.